Primary aluminium production relies entirely on electrical power, from the processing of ore (mainly bauxite) into the alumina (aluminium oxide) needed to make aluminium by electrolysis. Electrical energy costs represent a sizeable proportion of primary aluminium production expenses. The ever-expanding range of products that use or are made of aluminium means that global demand for this metal is constantly rising, pushing producers to seek ways to make its production as energy efficient as possible.http://www.iec.ch/etech/2011/etech_0911/ind-1.htm
Inert anode technology may have a revolutionary impact on the global aluminium industry. The tests are being carried out on a completely new 3kA pot in Krasnoyarsk (KrAZ) and, if successful, production tests on its inert anode pots will start in 2015. From 2017 the Company may start shifting its existing smelting capacities to inert anode technology, starting at KrAZ..http://www.aluminiumtoday.com/news/view/uc-rusal-pushing-ahead-with-inert-anode-development/aluminium-news
The cermets were prepared for aluminum electrolysis as inert anode. The microstructure of cermets inter anode was dense , the crystal of cermets growth ideally. The electric conductivity was stable and good, had the electric conductivity property of the semiconductor. The conductivity increased with temperature increasing. Electrolysis was conducted 12h at 850℃ in cryolite molten salt(CR=2.0, Al2O3 comtent 5.0% ), and the anodic current density was 1.0 A/cm2.The results showed that the cermets inert anode had high anti-oxidation, corrosion resistance and high conductivity. The back electromotive force was 2.45V, the decomposition voltage was 2.18V, the conductivity at 850℃ was 47S/cm, the annual corrosion rate was 23.68 mm/year.DOI10.4028/www.scientific.net/AMR.189-193.4377
Recent developments in the field of low-temperature electrolytes and electrolysis are considered. Although the investigations have not found fundamental problems in low-temperature aluminum electrolysis development as an industrial process, challenges remain in cell design, construction, and operation of cells with these emerging technologies.ecst.ecsdl.org/content/50/11/205.short
In the development of a computer control system for an aluminium electrolysis plant the basis ideas from modern control theory guided the work although a proper application of modern methods was not possible. The structure of optimal control systems was followed.The systems has been implemented on a CDC 1700 computer and tested in a production line on a group of 20 electrolysis cells for a long period of time. A significant increase in productivity has been recorded. The structure of the system allows a very flexible cooperation between the plant operators and the computer and is suitable for programming.DOI 10.1007/978-3-642-65798-6_5
During the production of aluminium in smelters, the anodes used in electrolysis cells have to be replaced frequently. Anode butts are usually placed on anode trays for transportation and cooling in the potroom, a process during which Hydrogen Fluoride (HF) is emitted in large quantities. The ambient air humidity reacts with the fluoride emitted by the hot bath and sticking onto the anode butts, producing HF emissions. HF is particularly toxic for the environment and human beings as well. With the collaboration of Alcoa Canada, STAS has developed the CAT / Covered Anode Tray, a special tray that reduces HF emissions by 0.055 kg per ton of aluminium, which represents 50% of the HF emitted from anode butts. Considering that the best smelters generate a total of about 0.28 kg of HF per ton of aluminium (for the whole process), the implementing of covered anode trays represents an HF reduction of 20% for a single smelter.The system, which is very simple, reduces contact between ambient air and the anode butts. A special sealing mechanism around the anode rod ensures an optimum result while minimising the operating costs of the system.
A new crust bin system is also used conjointly with the anode tray cover to further reduce HF emissions during the anode replacement process.http://www.stas.com/en/electrolysis-and-carbon/covered-anode-tray-cat.html
NiFe2O4–10NiO-based cermet inert anodes for aluminium electrolysis were prepared and their properties were investigated in a lab-scale electrolysis cell.The results show that the inert anodes exhibit good performance during electrolysis in molten salt cryolite at 960 °C, but according to the analyses of phase compositions and microstructures through XRD, SEM/EDX and metallographic analysis, the metal in the anodes is preferentially corroded and many pores are produced on the anode surface after electrolysis. The preferential dissolution of Fe in the NiFe2O4 phase may lead to the non-uniform corrosion of NiFe2O4 grains
http://www.sciencedirect.com/science/article/pii/S1003632613629349
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